Ionic liquid-based single drop microextraction and room-temperature gas chromatography for on-site ion mobility spectrometric analysis

The combination of ionic liquid-based headspace single drop microextraction (IL-HS-SDME) and room-temperature gas chromatography/ion mobility spectrometry (RTGC-IMS) is presented for the first time using the direct determination of trihalomethanes in waters as model analytical problem. The ionic liquid allows the transference of the analytes from the sample to the analytical system, at the same time that it provides an increase of the sensitivity and selectivity of the determination. An injection unit has been designed to permit the efficient volatilization of the analytes at room temperature and to avoid the entering of IL in the system. The direct combination allows the determination of the halocompounds in a rapid and simple way taking advance of their characteristic IMS spectra. The limits of the detection range between 0.1 ng mL(-1) (bromoform) and 0.9 ng mL(-1) (chloroform), the reproducibility of the system being better than 7.1% (RSD). The proposed coupling opens up a new horizon in IMS-based applications. (C) 2009 Elsevier B.V. All rights reserved.